"""
@file : 作业3
@author : wujiaxi
@Date : 2021/5/31

"""
qual = input("请输入空气质量指数：")
if qual == "Q":
    print("退出循环")
elif 0 <= int(qual) <= 50:
    print("空气质量状况为优")
elif 50 < int(qual) <= 100:
    print("空气质量状况为良")
elif 100 < int(qual) <= 150:
    print("空气质量状况为轻度污染")
elif 150 < int(qual) <= 200:
    print("空气质量状况为中度污染")
elif 200 < int(qual) <= 300:
    print("重度污染")
elif int(qual) > 300:
    print("严重污染")





